Chinese maritime authorities have said they will board and search ships which enter what Beijing considers to be its territorial waters.

Acting on new rules to be introduced on January 1, Chinese police on the island province of Hainan to the south-west of Hong Kong will be permitted by Beijing to carry out searches on foreign-flagged vessels.

The China Daily, a state sponsored English-language newspaper, reported: "Activities such as entering the island province's waters without permission, damaging coastal defence facilities, and engaging in publicity that threatens national security are illegal.

"If foreign ships or crew members violate regulations, Hainan police have the right to take over the ships or their communications systems, under the revised regulations."

China is locked in a series of maritime territorial disputes with a number of its neighbours.

Beijing has a longstanding but historically dormant claim to a large U-shaped swathe of the South China Sea and islands dotted in it.

The Philippines, Vietnam, Malaysia, Taiwan and Brunei all hold claims to various sections of the sea.

Satellite imagery of a tiny island in the sea, seen by Sky News, shows evidence of significant development. Both China and the Philippines have built runways and deep water harbours on two of their outcrops forming part of the Spratly Islands.

China also claims sovereignty of a number of islands in the East China Sea which Japan says are part of its territory. Beijing calls them the Diaoyu Islands; Tokyo refers to them as the Senkaku Islands.

International observers do not fear an imminent and intentional military clash between any of the nations involved. However, there are concerns that an accident between navies operating close to each other in defence of the territories could spark something more serious.

China has said that it will place new "surveillance ships" in parts of the South China Sea and the Yellow Sea.

Officials in Beijing have insisted that the Liaoning will only be used for training and surveillance but there are plans to build a number of new carriers within the next decade.

China, Japan and the countries of South East Asia are all major trading partners with the West. There is concern that any military escalation of the dispute in waters which straddle important shipping lanes could significantly impact on trade.